function be = function_of_be(JXe)
%% 初始化 be
be = zeros(3, 1);

%% 定义数值积分参数
kesi = [0.932469514203152, 0.661209386466265, 0.238619186083197, -0.932469514203152, -0.661209386466265, -0.238619186083197];
w = [0.171324492379170, 0.360761573048139, 0.467913934572691, 0.171324492379170, 0.360761573048139, 0.467913934572691];

for i = 1:6
    %% 插值函数及其导数
    fy = [1/2*kesi(i)*(kesi(i)-1);
        (1-kesi(i))*(1+kesi(i));
        1/2*kesi(i)*(kesi(i)+1)]; % 式(1.46)
    dfy_dkesi = [kesi(i)-1/2;
        -2*kesi(i);
        kesi(i)+1/2]; % 式(1.47)
    %% Jacobi 相关计算
    dx_dkesi = dfy_dkesi' * JXe; % 式(1.57)
    J = dx_dkesi; % 式(1.55)
    invJ = inv(J);
    dfy_dx = dfy_dkesi * invJ; % 式(1.54)
    %% be 计算
    be = be - w(i)*fy*det(J); % 式(1.63)
end

end